Answer: External segments are called metameres and internally, septa, or dividing walls, are located between the segments.
Explanation: I think it is
Hypothalamus is a part of the brain that links the nervous system to the endocrine system via the pituitary gland. It helps maintain the internal environment constant by regulating major processes in the body such as the heart rate and the body temperature. It is therefore, both a neural and endocrine organ.
Cephalization describes the process by which organisms develop a distinct head. The head of a cephalized organism contains a concentrated group of nerves, or brain, that controls the rest of the organism, as well as specialized organs for consumption and perception, like mouths, eyes and ears. Cephalized organisms exhibit a distinct division between parts of the body; they have a front, back, top and bottom. These animals comprise the bulk of animals that are encountered on a daily basis.
sea star following organisms exhibits cephalization